Saturday, November 05, 2011

Scientists uncover the secrets behind rapid tissue repair

10 October 2011

UK researchers have discovered how cells detect and respond to tissue damage. Their findings could open up new opportunities for improving tissue repair in patients after illness or surgery. When a tissue is wounded, cells detect damage via changes in their environment. Plasma leaking from broken blood vessels causes fibroblast cells to migrate into the damaged tissue, making the wound contract and plugging it by depositing substances such as collagen, which gives structural support to the tissue.

Now, researchers at the University of Bristol and the Wellcome Trust Centre for Cell-Matrix Research, University of Manchester - funded by the Wellcome Trust - have examined the signalling process that occurs in damaged tissues and identified the cellular mechanisms responsible for activating repair.

Lead author Dr Mark Bass said: "Each of these processes requires the turnover of cellular adhesions [repeated sticking and unsticking of cells], and the challenge has been to determine how cells detect tissue damage and modify their adhesive properties accordingly."

Using an imaging technique known as atomic force microscopy, the team were able to show how a protein, syndecan-4, triggers the uptake and redeployment of adhesive molecules. This novel sequence of signals enables fibroblasts and other cells to respond to changes in tissue structure and migrate along the matrix fibres which make up the skin. By moving towards a damage signal, cells are able to arrive at the wound far more quickly than if they searched for it randomly. This results in a very efficient healing response.

Dr Bass added: "We find that this signalling cascade is essential for efficient healing; this opens up considerable opportunities for improving tissue repair in patients."

Image: A scanning electron micrograph of the underside of a sticking plaster used to treat a razor blade cut. Credit: Anne Weston, LRI, CRUK, Wellcome Images.

Bass MD et al. A syndecan-4 hair trigger initiates wound healing through caveolin- and RhoG-regulated integrin endocytosis. Developmental Cell 2011 (epub ahead of print).

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